Different ingredients are used in the process of preparing chocolate, being cocoa powder, cocoa butter, cocoa paste, cocoa butter equivalent fats, sugar and emulsifier conventionally used. Additionally, there are other additional ingredients which can be added, as long as the Directive 2000/36/EC of the European Parliament and of the Council of 23 Jun. 2000 relating to cocoa and chocolate products intended for human consumption is fulfilled. Said Directive specifies the ingredients and proportions thereof in the different types of chocolates. These different types of chocolate are defined in Annex I of said Directive. This Directive also indicates that the addition of animal fats and their preparations which are not exclusively derived from milk, as well as the addition of flavoring agents which mimic the taste of chocolate or of milk fat, are prohibited.
The sugars most used in the manufacture of chocolate and substitutes are sucrose (also called saccharose), lactose (in milk chocolate) and polyalcohols. Sucrose is a disaccharide formed by two sugars (monosaccharides), glucose and fructose, chemically bound together. Lactose is also a disaccharide and is formed by the combination of glucose and galactose.
All these sugars are in crystalline form, however, sugar also exists is a non-crystalline amorphous form. This occurs, for example, when sucrose solutions are dried too quickly and there is no time for the individual molecules to form a crystalline structure as the water is removed. Sugar in amorphous form is an important factor to be taken into account in the manufacture of chocolate since it can affect the taste and the fluidity properties of liquid chocolate. The surface of amorphous sugar is very reactive and can easily adsorb any taste/flavor surrounding it. Thus, for example, if sugar is ground together with cocoa, some of the volatile compounds of the cocoa can be adsorbed by the amorphous sugar instead of escaping to the atmosphere, which will result in a chocolate with a more intense taste. However, the amorphous state is unstable and in the presence of water it is transformed into a crystalline material. Once said change has occurred, free water remains which is absorbed by the sugar molecules and makes them to bind to one another forming aggregates, which confer a gritty texture to the chocolate (undesirable). Furthermore, moistened sugar has a high risk of being microbiologically contaminated.
Although glucose and fructose linked together form the disaccharide saccharose, these monosaccharides are normally not used per se in the manufacture of products in which the process for their preparation requires mixing polar and apolar substances, such as the preparation of chocolate. Glucose, also known as dextrose, crystallizes as a monohydrate, is very difficult to dry completely and is very hygroscopic. Likewise, fructose, which is naturally present in fruits and in honey, is also very hygroscopic. This hygroscopicity of both molecules hinders its use in the manufacture of chocolate since the moisture which both molecules absorb from the air surrounding them makes liquid chocolate very viscous, since said moisture favors the binding of the sugar particles to one another. This high viscosity hinders the handling of said chocolate in liquid state and makes very special processing conditions be required, especially in terms of temperature and moisture, which increases the cost of the chocolate manufacturing process using said sugars. Another problem also arises in the refining of glucose, because its crystallization water content is released at 65° C. Even when refining temperatures lower than these are measured, at the time of applying pressure, temperatures releasing crystallization water are produced. Fructose is even more susceptible to pressure. This is one of the main reasons for which it is difficult to produce chocolate with a fructose base.
In this respect, the present invention achieves the introduction in the chocolate manufacturing process of rarely used sugars such as, among others, glucose and fructose. It thus provides broad alternatives to the chocolate industry, allowing the manufacture of chocolates with sugars from, for example, fruits or honey, and without resulting in an increase of the cost of the manufacturing process.
Honey is a food with a high energy value (˜337 Kcal/100 g) and with an easy digestion since it is almost exclusively made up of simple sugars, which do not require transformations and are directly assimilated, in addition to glucose and fructose, provides other compounds such as vitamins, proteins, mineral salts, etc, which are essential for the good functioning of the organism. Therefore, the consumption of honey is more recommendable than that of sugar.
Fruit has, in turn, an undeniable reputation from the nutritional and functional point of view, which will result in a better positioning of the chocolates obtained from fruit sugars (object of the present invention) compared with those prepared from purified and crystallized sugars. Since soluble fruit fractions are used among the main components thereof, fructose will be present at a higher concentration. This may be interesting because fructose is one of the sugars with the lowest glycemic index and it has been massively used for years in diets for diabetics and its use is authorized as a sugar-substituting natural sweetener.
On the other hand, there are many studies focused on achieving the incorporation of water in chocolate, among other reasons, to reduce the calorie content of chocolate. However, despite the extensive research conducted in this field, and the multiple patents relating to said incorporation of water, there are few satisfactory results in relation to the quality and organoleptic characteristics of the chocolate obtained. Thus, for example, it should be emphasized those which use emulsion as the route for incorporating water, as is the case of U.S. Pat. No. 5,120,566 (Baba et al., 1992), which describes a method for manufacturing chocolate with water, by directly mixing the chocolate with an aqueous ingredient, after rolling and conching, and emulsifying it with a nut paste to achieve a water-in-oil (W/O) emulsion. However, and unlike the chocolate obtained by means of the present invention, the chocolate obtained by this method does not have a crispy nature like conventional chocolate and is instead comparable to a chocolate cream (Beckett, 2000). Moreover, U.S. Pat. No. 5,468,509 (Schlup and Lioutas, 1995) describes a process for preparing milk chocolate with a water content of 1-16% by weight, in which the cocoa and the aqueous ingredient are mixed until obtaining a homogeneous mixture. The product obtained by means of this process has a plastic, homogeneous appearance, its fracturability and hardness being suitable with respect to conventional chocolate, although the product in liquid state behaves like a viscoelastic fluid, its viscosity and fluenciy limit being too high to be incorporated into the conventional process for preparing chocolate, which makes it uninteresting from the industrial point of view.
Taking into account these last technical problems, the present invention describes a composition through which the incorporation in the chocolate of both water and sugars rarely used in the process for preparing chocolate is achieved both at laboratory scale and at industrial scale. These objectives are achieved with the composition object of the invention, which is a lyotropic composition of carbohydrates in fats (hereinafter referred to as lyotropic composition) characterized in that it comprises at least a polar phase, a fatty phase and a surface-active agent. In relation to the processes for incorporating the carbohydrates in a non-polar medium such as fats, several techniques have been described in the state of the art. In industry, micronizations of the sugars are normally carried out, which sugars are dispersed in the fats and subsequently stabilized by means of tempering. Nevertheless, practice has demonstrated that achieving particle size within a narrowly defined spectrum defined between 6 and 30 μm is extremely difficult even when the grinding process is combined with a separation/classification step. When these degrees of fineness are not achieved, these dispersions are generally unstable and end up causing the decantation of the dispersed colloids. Another method for incorporating polar substances in non-polar substances is emulsion, however, emulsions are thermodynamically unstable (Salager et al. 2001).
Unlike emulsions, the composition of the present invention is stable and can therefore be stored without agitation both at room temperature (approximately 25° C.) and in refrigeration conditions (4-10° C.). In the context of the present invention, a composition is understood to be stable when no physical, chemical or microbiological change reducing the quality of the composition is observed for a given time period (time determined by the starting fat or fats of the fatty phase). Furthermore, it should be emphasized that in the present invention the emulsion can occur as an intermediate step for the formation of the lyotropic composition, which allows the lyotropic composition to behave as a liquid crystal.
A liquid crystal is a material having at least one intermediate phase between the isotropic liquid phase and the crystalline solid phase, according to the temperature and/or the concentration of its components in a determined solvent. Said phase is also called mesophase and, therefore, the liquid crystal is referred to as mesogenic. In this type of intermediate states, the molecules lack the positional order of a crystal, but are ordered orientationally. They are thus fluid phases with anisotropic properties. The molecules of mesogenic materials usually have a determined geometry facilitating the molecular packing in said anisotropic phases. The ordering is never perfect and only occurs at moderate temperatures, in which thermal agitation is not intense enough to destroy the liquid crystal structure.
Two types of liquid crystals can be distinguished. Thermotropic liquid crystals, the phase diagram of which depends only on the temperature, and the lyotropic liquid crystals, in which in addition to the temperature, the concentration of the compound in a solvent makes the phase diagram vary. In the case of lyotropic liquid crystals, the constituent molecules are usually amphiphilic, with a polar group which dissolves in water and a hydrophobic apolar chain. Thus, the systems with a surface-active agent mainly form mesophases of the lyotropic liquid crystal type, as is the case of the object of the present invention.
The lyotropic composition of the present invention is an at least ternary system comprising, for example, food fat-tensoactive-carbohydrates, which is obtained by means of adjusting the conditions of the synthesis process: pressure and temperature, to determined concentrations of the elements forming the ternary system. The ideal point of concentration of the constituent elements is reached by means of removing by evaporation the excess solvent present in the initial polar phase. The behavior of the resulting lyotropic composition is very similar, generally speaking, to that of the original fat, so the same types of storages, tanks and machinery can be used for its application.
Moreover, another important advantage of the lyotropic composition object of the present invention is that the carbohydrate source may be impure, containing other components different from carbohydrates, such as minerals, vitamins, amino acids, essential oils, fibers, etc., which the carbohydrate source can contain.
In relation to the flavors, many works have been carried out to understand the contribution of the components in the flavor and taste of the chocolate, also the notes have been classified as positive or negative in the sensory context of chocolate, the note of honey being very desirable. This note is present in cocoa in a very low dilution factor. A series of components related to this note have been identified in cocoa: 2-phenylethanol, phenylacetaldehyde, 2-phenylethyl acetate, 2,3,5-trimethyl-6-ethylpyrazine, 2-carboxyaldehyde-1H-pyrrole, furancarboxaldehyde, furfuryl alcohol and 2,5-dimethyl-4-hydroxy-3(2H)-furanone. A chocolate with a greater honey flavor has not been achieved up until now, however, the chocolate prepared from the lyotropic composition of the invention (using honey as the carbohydrate source) considerably increases the notes of honey in the final chocolate.
The lyotropic composition solves the problem of the introduction in the chocolate of natural flavors, whether they are single-variety or multi-variety flavors. By means of conventional processes it would not be excessively difficult to add natural flavors when the flavor is determined by a character impact compound, such as for example banana flavor (isopentyl acetate) or grape flavor (methylanthranylate). It is more difficult when the flavor is determined by several few compounds, such as apple flavor (ethyl-2-methylbutyrate, hexanal, trans-2-hexenal) and raspberry flavor (1-(p-hydroxyphenyl)-3-butanone, cis-3-hexen-1-ol, damascenone, α-ionone, β-ionone), and virtually impossible when the flavor can only be satisfactorily reproduced with a large number of compounds, representative examples are passion fruit flavor (ethyl butyrate, ethyl hexanoate, hexyl butyrate, hexyl hexanoate and peach flavor γ-lactone (C6, C8, C10), δ-lactone (C10), several esters, alcohols, acids, benzaldehydes) and strawberry flavor the aroma of which depends on several hydrocarbons, alcohols, aldehydes and ketones, acids, esters, sulfur compounds, etc. However, with the lyotropic composition of the present invention it is possible to obtain chocolates with fruit flavors the aroma of which would be difficult to obtain by means of flavoring with natural flavors, among others, strawberry and passing fruit.